The hemorrhoids, or piles, are swollen varicose veins in the mucous membrane inside or just outside the rectum.
One common cause of piles is constipation and the straining to eliminate hard, dry stool. The excessive pressure causes a fold of the membraneous rectal lining to slip down, thus pinching the veins and irritating them.
Women during pregnancies are particularly subject to the hemorroidal problem because of the pressure in the veins in the lower body area.
Other causes are diseases of the digestive tract resulting in anal infection, and cirrhosis of the liver, which obstructs blood flow and puts increased pressure on the hemorrhoidal veins.
Once the hemorrhoids are formed, they can further deteriorate or rupture by additional pressure during constipation and straining at stool, or by external pressure by long sitting (particularly if the piles are prolapsed or external).
The ruptured and bleeding piles are sensitive to infection; the swelling caused by inflamation affects, in turn, the hemorrhoids by pressing the veins.
The hemorrhoidal problems are self-accelerating and the prevention of the progressive deterioration of the problem is the essential condition of a successful treatment.
The treatment methods range from warm bath through ointments and suppositories to surgery or an injection chemotherapy to control bleeding and to eliminate the varicose veins. Often several methods are combined to address various aspects of the disease.
One approach to the treatment is to relieve the pain and to diminish the swelling by cooling of the hemorrhoidal tissue. For instance Cowie in U.S. Pat. No. 969,134 suggested the use of hollow insert filled with crushed ice or another cooling medium which was refilled for every use.
More recently Harris in U.S. Pat. No. 3,939,842 suggested a plastic rectal insert with encapsulated freezable liquid, preferrably water, equipped with a bulbous collapsible end. Both devices above have several shortcomings in common:
(1) The surface of the device may have very low temperature so that it can cause frost-bites to the sensitive rectal tissue. The frost-bites occur when the intracellular liquid is frozen, rupturing the cell membrane. This may happen even at moderately sub-zero temperatures if the contact between device and tissue is intimate and heat transfer efficient, which is the case for both devices.
(2) Neither of the devices is inherently disposable which can increase the risk of infection. Although the Harris device is intended to be disposable, it lacks any features preventing its multiple use. Its presumably higher cost, if compared with ointments or suppositories, may encourage its multiple use.
(3) Both devices have one single function, the cooling of the tissue in the rectal canal. This treatment has to be combined with other means, such as ointments, lubricants or suppositories etc., which support the treatment and the discomfort relief by delivering certain drugs, protective and lubricating layer onto the swollen tissue and by eventual softening the stool.
(4) Neither device can be applied without a lubricant.
Therefore, the freezable liquid encapsulated in a solid shell cannot utilize fully the beneficial cooling effect and introduces certain risks.
Suppositories cannot be used for the cooling effect because of their shape: the pressure of the sphincter squeezes them immediately from the rectal canal into bottom of the colon. This holds even for hydrogel suppositories, as described e.g. by Byrne and Aylott in U.S. Pat. No. 4,292,300, which could have otherwise sufficient heat capacity due to relatively high water content. The role of suppositories in general is drug delivery, and their cooling effect in the rectal canal was never suggested or anticipated. Therefore, suppositories in general differ substantially from the rectal inserts described either in the prior art or in the present invention.